Brake control system, self contained electronic brake control device therefor and methods of making and using the same

ABSTRACT

An automated electronic brake control device comprises an upright enclosure having a separable cover, the enclosure containing an energy source, a breakaway safety switch, a controller comprising a grade and motion detection device, timer, relay and circuit breaker and means for connecting the electronic brake control device to the electrical circuity of a towing vehicle and a towed vehicle. Preferably, the brake control device is mounted upon the towed vehicle and the controller has capabilities of sensing a change of velocity in at least one direction. Electric circuitry connects the braking circuitry of the towing vehicle to the braking system of the towed vehicle such that when towing vehicle brakes are applied, the brake control device supplies power to the braking system of the towed vehicle proportional to the sensed change in velocity.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of Applicant's parent patentapplication Ser. No. 09/675,395 filed on Sep. 29, 2000, now U.S. Pat.No. 6,364,432.

This application is a non-provisional application under 35 U.S.C. 111(a) of its provisional application Ser. No. 60/168,688, filed Dec. 3,1999, provisional application Ser. No. 60/183,503, filed Feb. 17, 2000,and provisional application Ser. No. 60/230,767, filed Sep. 7, 2000.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a self contained electronic braking system formounting on a towed vehicle and then being attached to the brakingcircuitry of the towing vehicle to provide for automatic energizing ofthe braking system of the towed vehicle when the brakes of the towingvehicle are applied.

2. Prior Art Statement

Current brake control for vehicles being towed comprises a hand operatedor electronic brake controller mounted in the towing vehicle near thedriver. Braking of the towed vehicle requires that the driver attend tothe brake lever or controller with one hand while attempting to steerwith the other hand and thus safety hazards include potential loss ofcontrol of both vehicles. Most current trailer braking systems also donot provide for braking control on the towed vehicle when the towedvehicle becomes separated from the towing vehicle or when the towedvehicle is parked separate from the towing vehicle.

Pokrinchak, et al., in U.S. Pat. No. 3,738,710 issued on Jun. 12, 1973provides an elementary timing circuit in a towed braking system todifferentiate between a momentary closure and a steady closure of atowed vehicle braking switch and thus electric trailer braking isdependent upon the duration of the closure of the stoplight switch ofthe towing vehicle.

It is known to provide for a truck-trailer hydraulic brake systemcomprising a trailer brake system including an electric motor actuatedby an electrical circuit through a control means associated with thebrake pedal onboard the tractor or a safety switch connected between thetractor and the trailer. No means for sensing motion is provided. Forinstance, see the U.S. Pat. No. 3,951,464 to Donahue, et al., issued onApr. 20, 1976.

It is known to provide breakaway protection for electrically controlledtrailer brakes by placing an additional battery on the trailer connectedin parallel with the battery on the towing vehicle through a breakawayswitch in which primary braking control is rheostatically controlled bythe driver. For instance, see the U.S. Pat. Nos. 4,052,695 and 4,066,966issued on Oct. 4, 1977 to Philip E. Myers and on Jan. 3, 1978 to DonaldL. Davis, respectively.

It is known to provide an electrical surge braking system for a trailerwherein the electrical brakes of the trailer are energized when thetrailer surges forwardly relative to the towing vehicle as the effectiveresistance of a resistor associated with one hitch member decreases as awiper associated with another hitch member moves along the resistor. Forinstance, see the U.S. Pat. No. 4,222,614 issued on Sep. 16, 1980 toJohn A. Spechko. Similar devices are provided for hydraulic trailerbraking systems.

Also, it is known to provide a braking system for a towed vehiclemanually actuated by the driver of the towing vehicle and wherein thetowed vehicle has an onboard battery to provide for braking of the towedvehicle in case of separation from the towing vehicle wherein braking isactuated by a separable connector between the towed vehicle and thetowing vehicle when the vehicles become separated. For instance, see theU.S. Pat. No. 3,907,071 issued on Sep. 23, 1975 to Wm. H. S. Wells.

It is also known to provide a towing vehicle mounted brake controllerwherein braking of a towed vehicle is manually actuated by the driver,initiated by a signal from the towing vehicle brake system and whereinthe amount of towed vehicle braking is controlled by a pendulum typegrade and motion detection device on the towing vehicle. For instance,see the U.S. Pat. No. 3,909,075 issued on Sep. 30, 1975 to Pittet, Jr,et al.

Robert C. Snyder in U.S. Pat. No. 4,196,936 issued on Apr. 8, 1980provides for electric or hydraulic trailer braking from a series ofcomponents comprising a brake controller mounted in the tractor througha separate wiring harness wherein power is supplied to a variablefrequency oscillator when the brake pedal is depressed. The series ofcomponents uses a hall effect sensor for sensing of the deceleration orlateral movement of the towing vehicle and for applying the brakesdependent upon the magnitude of the motion.

Frait, et al., in U.S. Pat. No. 4,721,344 issued on Jan. 26, 1988 andU.S. Pat. No. 4,726,627 issued on Feb. 23, 1988, respectively, providefor electric trailer braking from a brake controller mounted near thedriver of a towing vehicle through a separate wiring harness whereinpower is supplied to the pulse width modulator of the controller onlywhen the brake pedal is depressed or when a manually controlled lever ismoved to the on position. The controller uses a pendulum for sensing ofthe deceleration of the towing vehicle and generates a signalrepresenting the magnitude of the deceleration.

Additionally, it is known to provide a stability control system for avehicle to prevent swerving and swaying comprising means for sensinglateral acceleration forces acting upon the vehicle and energizing abrake in response to signals wherein the means for sensing lateralacceleration is a pair of inclined mercury switch assemblies, halleffect or pendulum sensors. For instance, see the U.S. Pat. No.3,861,489 issued on Jan. 21, 1975 or the U.S. Pat. No. 3,908,782 issuedon Sep. 30, 1975 both to Lang, et al.

Finally, it is further known to provide a method of controlling brakeson a trailer by sensing the rate of deceleration and inclination of thetowing vehicle, generating variable deceleration and variableinclination signals, sending a brake amperage output signal to thebrakes of the trailer and continuously proportioning the brake amperageoutput in accordance with both the deceleration and inclination signals.For instance, see the U.S. Pat. No. 6,012,780 issued on Jan. 11, 2000,to Mark E. Duvernay.

The above cited braking systems, though usable in their respectiveenvironments, do not have means of transferring all control of anelectronic braking system from the towing vehicle to the towed vehicle.The prior art trailer braking systems do not describe a self containedelectronic braking control device mounted upon the trailer wherein thebraking control device comprising a means for sensing deceleration ofthe trailer and means for actuating the braking system of the trailereither independent of a signal from the towing vehicle or using thebraking light circuit of the towing vehicle for actuation of the brakeson the towed vehicle. Therefore, there is a great need for an electricor hydraulic trailer braking system for use with a trailer having atleast one pair of wheels fitted with electrically or hydraulicallyactuated brakes wherein the trailer braking system is a self containedelectronic braking control device mounted upon the trailer, the brakingcontrol device comprising a means for sensing deceleration of thetrailer and means for actuating the brakes of the braking system of thetrailer, the self contained electronic braking control device havingelectric circuitry connecting the braking circuitry of the towingvehicle to the braking system of the towed vehicle wherein the brakes ofthe braking system of the towed vehicle are automatically energized toan initial engagement state upon sensing a braking signal from thetowing vehicle.

SUMMARY OF THE INVENTION

Heavy towed vehicles, particularly two and three axle vehicle trailersare required to have electric brakes operable from the towing vehicle.Such brakes usually require some hand operation by the driver of thetowing vehicle presenting hazards to the driver and the other vehicleson the road. Other towed vehicles are equipped with a hydraulic brakingsystem operated by a surge connection at the towed/towing vehicle hitchlocation or with an electric solenoid operating a hydraulic cylinderwith an electric, pneumatic or hydraulic signal from a towing vehicle.

Therefore, it is an object of this invention to provide an electronictrailer braking system for a trailer having at least one pair of wheelsfitted with electrically actuated brakes wherein the trailer brakingsystem is a self contained electronic braking control device mountedupon the trailer, the braking control device comprising a means forsensing deceleration of the trailer and means for actuating theelectrically actuated brakes of the trailer independent of a signal fromthe towing vehicle.

It is still another object of this invention to provide an automatedelectronic braking system comprising an energy source, a chargingcircuit, a grade and motion sensing device, a timer, a relay, a circuitbreaker, a breakaway safety switch, a seven wire male plug forconnecting to a cooperating female connector on a towing vehicle and afemale socket plug for connecting to a seven wire male plug of a towedvehicle.

It is yet another object of this invention to provide an automatedelectronic braking system which may be mounted either within the towingvehicle wherein a complete brake wiring harness from a location near thedriver to the braking system on the towed vehicle is installed and usedto connect and actuate the electric brakes of the towed vehicle orwherein the automated electronic braking system is mounted on the towedvehicle and uses the braking light circuit of the towing vehicle foractuation of the electric brakes of the towed vehicle. When mounted onthe towed vehicle, electric circuitry connects the braking circuitry ofthe towing vehicle to the braking system of the towed vehicle such thatwhen towing vehicle brakes are applied, the braking system of the towedvehicle is automatically energized and the electronic brake controldevice containing the grade and motion device senses incline, lateralmotion and/or braking and hence supplies power to the braking system ofthe towed vehicle dependent upon the slope of the grade, the severity ofthe motion or both. When made a part of the towing vehicle, a breakawayswitch is in parallel connection with the electrical connection betweenthe towing vehicle and the towed vehicle and separated from theelectronic brake control device by the wiring harness. Generally, theenergy source for the onboard towed vehicle mounted braking system isintegral therewith but may be a separate battery, an array of solarcells, the towing vehicle energy source, a direct current or analternating current source, a capacitor or an energy source resident inthe towed vehicle or in the load carried by the towed vehicle.Similarly, the energy source for the braking system having thecontroller mounted within the towing vehicle is generally carried by thetowing vehicle but may be one of the alternate forms recited above. Theautomated electronic braking system may also employ an internal charger,an external charger or both when an internal energy source is used andmay also employ a seven wire to four wire adaptor for use with towingvehicles having a four wire plug.

It is another object of this invention to provide a self containedelectronic brake control device comprising an upright enclosure having aseparable cover, the enclosure containing an energy source, a brakecontroller, at least one relay and means for connecting the electronicbrake control device from a towing vehicle to a towed vehicle.

One object of this invention is to provide a retrofit for an existingtowed vehicle with a self electronic brake control device mounted uponthe towed vehicle wherein a 4 wire female connector for connecting theelectronic brake control device to a 4 wire male plug from the towingvehicle and a 4 wire male plug for connecting the electronic brakecontrol device to a 4 wire female connector of the towed vehicle thesepigtails used to connect the control device to the electrical system ofthe towed and towing vehicle.

Still another object of this invention is to provide a retrofit for anexisting towed vehicle with a self electronic brake control devicewherein a 4 wire female connector for connecting the electronic brakecontrol device to a 4 wire male plug from the towing vehicle and a 7wire male plug for connecting the electronic brake control device to a 7wire female connector of the towed vehicle these pigtails used toconnect the control device to the electrical system of the towed andtowing vehicle.

Yet another object of this invention is to provide a retrofit for anexisting towed vehicle with a self electronic brake control devicewherein the means for connecting comprises a 7 wire female connector forconnecting the electronic brake control device to a 7 wire male plugfrom the towing vehicle and a 7 wire male plug for connecting theelectronic brake control device to a 7 wire female connector of thetowed vehicle these pigtails used to connect the control device to theelectrical system of the towed and towing vehicle.

One important object of this invention is to provide a retrofit for anexisting towed vehicle with a self electronic brake control devicewherein a means for connecting comprises splice connectors andconnecting wires for connecting the electronic brake control devicedirectly to a wiring loom resident within the towed vehicle.

It is also an object of this invention to provide an electronic trailerbraking system for a towed vehicle having at least one pair of wheelsfitted with hydraulically actuated brakes wherein the towed vehiclebraking system is a self contained electric/hydraulic braking controldevice mounted upon the towed vehicle, the braking control devicecomprising a means for sensing deceleration of the trailer and means foractuating the hydraulically actuated brakes of the trailer either from asignal from the towing vehicle braking circuit or independently of asignal from the towing vehicle.

One important object of this invention is to provide a retrofit for anexisting towed vehicle with a self electronic brake control devicewherein a means for connecting comprises splice connectors andconnecting wires for connecting the electronic brake control devicedirectly to a wiring loom resident within the towed vehicle, and atleast one hydraulic line for connecting a hydraulic pump of the selfcontained control device to the hydraulic brakes of the towed vehicle.

A significant object of this invention is to provide a method ofcontrolling the braking of a towed vehicle using a braking controldevice onboard the towed vehicle, the braking control device comprisingan energy source, a means for sensing deceleration of the towed vehicle,a means for generating a braking signal and a means for energizing thebrakes of the towed vehicle. The method comprises the steps of sensingdeceleration of the towed vehicle, determining a rate of deceleration ofthe towed vehicle, sensing a braking signal from a towing vehicle towingthe towed vehicle, generating a braking signal within the brakingcontrol device wherein the braking signal is proportional to the rate ofdeceleration, energizing the brakes of the towed vehicle to initialengagement from the energy source upon sensing the braking signal fromthe towing vehicle and applying energy from energy source to the brakesof the towed vehicle proportional to the braking signal.

Another significant object of this invention is to provide a method ofcontrolling the swaying of a towed vehicle using a braking controldevice onboard the towed vehicle. The method comprises a means forgenerating a swaying signal, a means for generating a braking signal anda means for energizing the brakes of the towed vehicle. The steps of themethod include sensing at least two successive lateral movements of thetowed vehicle within a given time, generating a swaying signal uponsensing the lateral movements, determining a rate of lateral movement ofthe towed vehicle, generating a braking signal within the brakingcontrol device wherein the braking signal is proportional to the rate oflateral movement and energizing the brakes of the towed vehicleproportional to the signal.

The primary purpose of the automated electronic brake control system ofthis invention mounted on the towed vehicle is to remove towed vehiclebraking control devices from of the towing vehicle and transfer alltowed vehicle braking functions to the towed vehicle by energizing thebraking system of the towed vehicle from the braking system of thetowing vehicle. The alternate purpose of the automated electronic brakecontrol system of this invention mounted in the towing vehicle is toeliminate the manual operations required by the driver by providing abrake controller having capabilities of sensing a change of velocity inat least one direction and an automated system to apply the brakesdependent upon the severity the change of velocity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of the components of one embodiment of the selfcontained electronic brake control device of this invention in anenclosure showing the electric circuitry connecting the components.

FIG. 2 is an electrical diagram of the preferred embodiment of the selfcontained electronic brake control device of this invention shownconnected to an existing wiring loom of a towed vehicle.

FIG. 3 is an exploded view of the preferred embodiment of the selfcontained electronic brake control device of this invention shown abovea mounting location on a towed vehicle.

FIG. 4 is a plan view of one embodiment of a means for connecting theself contained brake control device of FIG. 1 to a towing vehicle and atowed vehicle.

FIG. 5 is a plan view of another embodiment of a means for connectingthe self contained brake control device of FIG. 1 to a towing vehicleand a towed vehicle.

FIG. 6 is a plan view of another embodiment of a means for connectingthe self contained brake control device of FIG. 1 to a towing vehicleand a towed vehicle.

FIG. 7 is an exploded view of the preferred embodiment of the selfcontained electronic brake control device of this invention for anelectric/hydraulic towed vehicle braking system shown above a mountinglocation on a towed vehicle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the various features of this invention are hereinafter describedand illustrated as an automated electronic trailer brake control systemwhich comprises an upright enclosure having a separable cover, theenclosure containing an energy source, a grade and motion detectiondevice, a timer, a relay, a circuit breaker, a breakaway safety switch,a seven wire male plug for connecting to a cooperating female connectoron a towing vehicle and a female socket plug for connecting to a sevenwire male plug of a towed vehicle with electric circuitry connecting thebraking circuitry of the towing vehicle to the braking system of thetowed vehicle such that when brakes are applied, the braking system ofthe towed vehicle is automatically energized and the grade and motiondetection device supplies power to the breaking system of the towedvehicle dependent upon the slope of the grade, the severity of themotion or both, it is to be understood that the various features of thisinvention can be used singly or in various combinations thereof as anautomated electronic trailer brake control system for either the towingor towed vehicle as can hereinafter be appreciated from a reading of thefollowing description.

Referring now to FIGS. 1, 2 and 3, the automated electronic brakecontrol system of this invention is generally referred to with thenumeral 10, electronic brake control system shown in an enclosure 1wherein enclosure 1 is preferably mounted onboard a towed vehicle tongue200. Electronic brake control system 10 preferably includes an energysource 5 such as onboard battery 20, a grade and motion detection device30, a battery charger 100 and may also include a separate timer 40, aseparate relay 80, a separate circuit breaker 60, a breakaway safetyswitch 70, a seven wire male plug 50 for connecting to a cooperatingfemale connector on towing vehicle and a female socket plug 90 forconnecting to a seven wire male plug of a towed vehicle. Grade andmotion detection device 30 preferably comprises a braking controller 15commonly used in the industry wherein controller 15 may use a G-forceindicator to sense positive or negative changes in motion or at leastone pendulum, hall effect or the like sensor for sensing incline,lateral movement and/or braking G-force wherein grade and motiondetection device 30 outputs either a digital or electrical signalproportional to change in motion in the sensed direction. The outputsignal of grade and motion detection device 30 is a braking signaloutput through terminal 33 supplying braking force to the brakes of thetowed vehicle braking system. As grade and motion detection device 30outputs a signal proportional to the amount of acceleration in thesensed direction, the braking force output through terminal 33 is alsogenerally proportional. The braking signal may be generated based on Xaxis acceleration, that is, the change in forward or backward motion ofthe towing/towed vehicle package or on Y axis acceleration transverse tothe direction of motion of the towing/towed vehicle package. It isunderstood here, that acceleration refers to a change in velocity in anyof the four directions, ±X, ±Y, sensed by grade and motion detectiondevice 30. In addition, grade and motion detection device 30 maymodulate the output signal based upon the change in grade, that is, achange in the ±Z direction thus effectively modulating the change invelocity in at least one of the ±X, ±Y directions.

Grade and motion detection device 30, in this preferred embodimentherein described, contains a G-force indicator to sense a change invelocity and/or grade as set forth above. The preferred G-forceindicator is model ADXL202, a dual axis accelerometer provided by AnalogDevices, One Technology Way, Norwood, Mass. wherein the G-forceindicator comes packaged as a 14 pin surface mount integrated circuit(IC). The digital signal output for the separate signals may be measureddirectly with a microprocessor counter wherein each output signal is aratio of the pulsewidth to the period. The period is adjustable from 0.5ms to 10 ms by a variable resistor while the pulsewidth is alteredwithin separate X and Y sensors. The G-force indicator is able tomeasure acceleration in any direction as the null output signal is setat 50% of the duty cycle. Therefore, a signal is generated when thepulsewidth is not equal to the period. Since the G-force indicator cansense movement force up to 2 times the force of gravity in eitherdirection along both the X and Y axes and the number of counts withinthe IC increases linearly therewith, the output signal is linear fromthe null point to a maximum. The digital output signal can then beconverted to an analog electrical signal to increase braking force.Typically, in an electrically actuated braking system, braking voltageincreases from an electrical signal equal to approximately 20% of energysource 5 to a maximum of the output of energy source 5 linearly as theoutput from the G-force indicator increases linearly. Braking voltagebegins at an electrical signal equal to 20% of energy source 5 as thislow voltage sets the electric brake coil in close proximity to thebraking surface of electric braking systems upon energizing the brakingcircuit, that is, generally upon depressing the brake pedal of thetowing vehicle. Any increase in braking voltage causes the braking padof the electric brake coil to frictionally engage the braking surface ofthe drum with a force proportional to the voltage in the braking coilthus pulling a braking arm therealong pressing the braking shoes of theelectrically actuated brakes against the inside surface of a drum.Though the braking voltage typically increases linearly from anelectrical signal equal to 20% of energy source 5 upon initiation, atleast one specific map of desired braking force may be stored within amemory chip in the circuitry of controller 15 thus causing braking forceto rise more rapidly reaching the maximum braking force before theG-force indicator has reached its fill output. Conversely, the map of adesired braking signal could cause the braking force to rise moreslowly. The internal workings of the electric brake pad, coil, shoes anddrum are well known in the art and need not be repeated here.

Electronic brake control system 10 preferably has means to define to themicroprocessor therewithin the type of braking system being connectedthereto, the type of wiring system within each of the towed and thetowing vehicle and, when necessary, the type of controller 15 usedtherewithin. For instance, DIP switches may be employed to differentiatebetween an electric/electric braking system and an electric/hydraulicbraking system. These DIP switches may also be set to differentiatebetween a 4 wire flat connection to the towing vehicle and a 7 wireround connection to the towed vehicle or another combination ofconnections between the towed and towing vehicles. Where a controllerhaving only capabilities of sensing a change in forward motion, DIPswitches may be set to disable the sway correction portion of electronicbrake control system 10. Likewise, the means to define may be used toredefine to the microprocessor components which have been added toelectronic brake control system 10 installed after the initialinstallation thereof. For instance, if controller 15 having onlycapabilities of sensing a change in forward motion is replaced withcontroller 15 having multiple direction sensing capabilities, the DIPswitches may be changed to reflect the new capabilities. Though DIPswitches have been cited as one means to define to the microprocessor,pre-programmed chips may also be advantageously used. Furthermore, an 7,9 or 15 pin, parallel, serial or USB input port in electronic brakecontrol system 10 connected to the microprocessor may be utilized toreprogram the microprocessor using an external computer.

Preferably, electronic brake control system 10 has a self diagnosticroutine within the microprocessor to sense faults in any of the circuitswithin electronic brake control system 10, the towing vehicle brakingsystem or the towed vehicle braking system wherein the self diagnosticroutine has an output signal to the operator of the vehicle. One meansof alerting the operator is by a radio frequency signal to a hand heldremote receiver/transmitter carried by the operator. The remotereceiver/transmitter may be fitted with an LED which when a fault isdetected in the self diagnostic routine, the LED is lighted alerting theoperator. The remote receiver/transmitter may also be used to changeoperation of electronic brake control system 10 by sending a radiofrequency signal from the hand held remote receiver/transmitter to themicroprocessor within electronic brake control system 10 wherein theradio frequency signal may be used to initially set the brakes shoes inclose proximity to the drum, disable or enable the swaying capabilitiesand/or apply braking force to the brakes of the towed vehicle brakingsystem or other capabilities programmed into the microprocessor.

Controller 15 contained within grade and motion device 30 may generate asmall output when tilted in at least one direction and therefore thesignal output may be used to initially level grade and motion device 30thus making installation easier for the user. Leveling may beaccomplished using the DA (digital to analog) converted signal orvoltage outputs from other pins on the IC as the X and Y sensors withinthe IC each have a voltage output in addition to the digital outputs.The actual duty cycle output, or alternately the voltage output, varieswith orientation of the IC and thus orientation of the IC provides for adifferent braking force in one direction along the axis of the IC whencontroller 15 containing grade and motion device 30 experiences a grade.For instance, with the IC mounted vertically with pin 1 at the top, theduty cycle is 62.5% while when reversed vertically with pin 1 at thebottom the duty cycle drops to 37.5%. Thus, it may be advantageous toplace the IC within controller 15 in grade and motion device 30 with pin1 facing in the −X direction such that a negative change in grade in the+X direction, that is, a downslope, would result in a slightly greaterbraking force when grade and motion device 30 is tilted relative to theEarth's surface with the pin 1 end rising. By thus mounting the IC withthe pin 1 end facing in the −X direction a greater braking force may begenerated in the forward movement direction of a towing/towed vehiclepackage, especially on a downslope, as the force required to brake apackage going forward at cruising speed would be greater than the forcerequired to brake the package while backing.

The IC may have a piezoelectric crystal in each of an X sensor and a Ysensor for sensing acceleration along the X and Y axes and as such maymeasure acceleration in either direction therealong, ie. ±X, ±Y. As theX and Y sensors act independently, acceleration in a direction betweenthe axes may also be sensed as both X and Y sensors would detect achange in velocity along these orthogonal axes. The digital output isthus an algebraic sum of the outputs of both sensors, this algebraic sumused in grade and motion device 30 to provide for a braking force hereindescribed. Of course, the signals from the X and Y sensors may bemodified, amplified or modulated to provide for different outputs in thevarious directions to allow for a different algebraic sum other than thesum of squares. For instance, the output signal of the Y sensor may bemade to output a signal independent of the braking light circuit of thetowing vehicle to automatically arrest sway wherein the output signal ofthe Y sensor would greater or lesser than a signal from the X sensor fora given amount of motion. Though piezoelectric crystals are preferredfor X and Y sensors as these piezoelectric crystals effectively have nomoving parts, other motion detection devices may be used within theG-force indicator as will hereinafter be fully described. It is readilyapparent here, that with the grade and motion device 30 of the preferredembodiment of the invention having the G-force indicator therein, that abraking force will be generated upon backing a towed vehicle. Thus, thegrade and motion device 30 and the braking system 10 of this inventionusing the brake controller 15 are not limited to forward movement as isprevalent with conventional brake controllers.

Furthermore, as controller 15 containing the G-force indicator can sensea change in velocity laterally to the direction of movement of thetowed/towing vehicle package, swaying of a towed vehicle can readily becorrected. Though the change in velocity laterally would generally beless than that required in bring the package to rest, the proportionaloutput of the sensor in the lateral direction, herein the Y sensor,would apply braking force to the electric brakes of a towed vehicle at alow level thereby correcting any swaying of the package. Thus, no actionby the operator of the vehicle is required to arrest swaying of a towedvehicle providing this improved measure of safety.

Referring now specifically to FIG. 2, an electronic trailer brakingsystem of a trailer having at least one pair of wheels fitted withelectrically actuated brakes is fitted with a self contained electronicbraking control device 10 comprising grade and motion device 30containing controller 15, an energy source 5 and charging device 100.Electronic braking control device 10 is preferably mounted at a locationselected by the owner or manufacturer upon or within the towed vehicleor trailer, the braking control device comprising a means for sensingdeceleration of the trailer and means for actuating the electricallyactuated brakes of the trailer independent of a signal from a vehicletowing the trailer. Preferably, as electronic braking control device 10is mounted onboard the towed vehicle with energy source 5 mounted withinelectronic braking control device 10, in case of separation of the towedvehicle from the towing vehicle breakaway switch 70 becomes separatedand braking control device 10 senses deceleration in at least onedirection. Thus, braking force is applied directly to the electricbrakes of the towed vehicle through connecting wire 77 through nowclosed switch 70, through connecting wire 77 to brake wire connection 73on brake wire 117. In this manner, braking force is applied at fulleffect as energy source 5 is directly connected to the electric brakesof the towed vehicle and thus the magnetic coil receives the full 12 VDCenergy of battery 20 wherein the magnetic coil becomes firmly attractedto the metallic pad dragging the brake arm therealong effectivelylocking the electric brakes of the towed vehicle.

In the embodiment shown in FIG. 2, controller 15 contains a G-forceindicator within an integrated circuit and also contains relay 80 andtimer 40, wherein these components are mounted on a circuit board withincontroller 15. Thus, controller 15 may be used as a full function brakecontroller operating in conjunction with the braking system of the towedvehicle to provide for towed vehicle braking as well known in the art.However, as controller 15 of this invention contains a G-force indicatorfor sensing acceleration in at least one orthogonal axis andproportionally applies braking force based on sensing a change invelocity without intervention by the operator of the towing vehicle,greater safety with towed/towing vehicle packages is provided. Ofcourse, the pendulum or hall effect operated brake controllers known inthe art may be modified to use only the grade and/or motion sensingelements therein wherein at least one of these brake controllers isinstalled in enclosure 1 as controller 15.

Referring to FIGS. 1-7, self contained electronic brake control device10 comprises an upright enclosure 1 having a separable cover 204, afirst compartment 202 and a second compartment 201, second compartment201 containing an energy source 5, preferably a high capacity dry cellbattery 20. First compartment 202 contains brake controller 15 and means49 for connecting electronic brake control device 10 to the brakingsystem of a towing vehicle and the towed vehicle.

Though plugs 50, 90 in FIG. 1 are shown as 7 wire male & female plugsrespectively each mounted in a wall of enclosure 1, these plugs 50, 90could comprise 4 wire male & female connecting plugs respectively onpigtails extending from enclosure 1, wherein for instance, referring nowto FIG. 4, means 49 for connecting may comprise a 4 wire femaleconnector 56 for connecting electronic brake control device 10 to a 4wire male plug 57 from the wiring harness 53 of the towing vehicle and a4 wire male plug 57 for connecting electronic brake control device to a4 wire female connector 56 to the wiring loom 51 of the towed vehicle.Likewise, referring now to FIG. 5, means 49 for connecting may comprisea 4 wire female connector 56 for connecting electronic brake controldevice 10 to a 4 wire male plug 57 from the wiring harness 53 of thetowing vehicle and a 7 wire male plug 59 for connecting electronic brakecontrol device to a 7 wire female connector 58 to the wiring loom 51 ofthe towed vehicle. In yet another embodiment as shown in FIG. 6, means49 for connecting may comprise a 7 wire female connector 58 forconnecting electronic brake control device 10 to a 7 wire male plug 59from the wiring harness 53 of the towing vehicle and a 7 wire male plug59 for connecting electronic brake control device to a 7 wire femaleconnector 58 to the wiring loom 51 of the towed vehicle. Preferably,however, referring now to FIG. 2, means 49 for connecting comprisessplice connectors 81, 82, 101, 91, connecting wires 211, 213, 212 and215 respectively and brake wire 117 for connecting electronic brakecontrol device 10 from controller 15 directly to wiring loom 51 residentwithin the towed vehicle.

Referring now to FIG. 1, electronic brake control device 10 may comprisesuch a modified controller 15 along with energy source 5, charging unit100, timer 40, relay 80, circuit breaker 60, breakaway safety switch 70,means 49 for connecting electronic brake control device 10 to theelectrical circuity of a towing vehicle and a towed vehicle. In thisembodiment, means 49 for connecting comprises a 7 wire male plug 50 forconnecting to a cooperating female connector on the towing vehicle andfemale socket plug 90 for connecting to a mating 7 wire male plug of thetowed vehicle. It is fully understood here, that though the descriptionof male and female plugs 50, 90 respectively, shown schematically inFIG. 1 is used herein in a particular location with reference toelectronic brake control device 10, that these plugs 50, 90 may bereversed to accommodate various towed vehicle manufacturers'specifications. Furthermore, when it is desired to retrofit an existingtowed vehicle with electronic brake control device 10 of this inventionwithout replacing the existing 4 wire wiring plugs on either the towedor towing vehicle, plug 50 may receive a 7 wire female connector 58 of a7 wire to 4 wire pigtail having 7 wire female connector 58 on one endand a 4 wire female connector 56 on the opposed end thereof wherein 4wire female connector 56 is adapted to be affixed to the towing vehiclehaving a 4 wire male plug 57 connected to the towing vehicle wiringharness 53. Such a pigtail would appear similar to FIG. 5 as if controldevice 10 as shown in this figure were omitted.

In self contained electronic brake control device 10 of FIG. 1,breakaway safety switch 70 comprises a first connector 75 affixed to thetowing vehicle and a second connector 78 affixed to the towed vehicle,where second connector 78 may be installed in a wall of brake controldevice 10, the braking system of the towed vehicle actuated uponseparation of first connector 75 of breakaway safety switch 70 fromsecond connector 78. Breakaway safety switch 70 used in this inventionis preferably a normally open switch when first connector 75 isinstalled into second connector 78 and wherein when first connector 75is removed from second connector 78, breakaway safety switch 70 closesapplying full power of energy source 5 to the towed vehicle brakes asthe brakes become directly connected to energy source 5 upon separationof the parts 75, 78 of breakaway safety switch 70.

Breakaway safety switch 70 of electronic brake control device 10 of theinstant invention also constitutes a parking brake when the towedvehicle is at rest and the first connector 75 is separated from secondconnector 78. As electronic brake control device 10 is normally providedwith its own power source 5 and may have an alternate solar panel (notshown) to maintain the charge, removal of first connector 75 ofbreakaway connector 70 from second connector 78 of the towed vehicleautomatically energizes the braking circuit of the electronic brakecontrol device 10 thereby applying brakes to the towed vehicle whenparked.

Breakaway safety switch 70 of self contained electronic brake controldevice 10 may alternately constitute an emergency brake when firstconnector 78 is separated from second connector 75 when for instance,the towed vehicle is moved with an open vehicle such as a tractor, bypermitting the operator of the open vehicle to use first connector 78 asan actuating device for emergency stopping of the towed vehicle asagain, the brakes of the towed vehicle become directly connected to theonboard energy source 5 of device 10.

System 10 may additionally employ a charger 100 for maintaining chargeon battery 20, a battery condition meter 120 and a switch 130 forenergizing battery condition meter 120. Charger 100 may be a tricklecharger mounted onboard control system 10 and receive power from thetowing vehicle by being connected to the green wire 112 as shown inFIGS. 1 and 2 at connection point 101. In the conventional 4 wire wiringsystem for towed vehicles, green wire 112 carries current for therunning lights, the brown wire 111 receives right hand turn signals or abrake signal, the red wire 113 receives left hand turn signals or abrake signal and the white wire 115 is system ground. In a 7 wire wiringsystem for towed vehicles, these 4 wires are again conventional and ablack wire 114 provides auxiliary power wire, a yellow wire 116 isauxiliary ground while the blue wire 117 is the trailer brakeconnection. Normally, a four wire flat connector, hereinafter, four-flatconnecter, is utilized for connecting the towing vehicle to the towedvehicle, these four-flat connectors provided on most rental trailers,boat trailers, utility trailers and the like which are in use by thegeneral public wherein the wiring loom 51 is typically constructed of 16gauge wire and therefore have insufficient current carrying capacity fora electric trailer brakes. Therefore, the braking system 10 of thisinvention is made for use with either a seven wire system or a four wiresystem by the unique circuitry described in the instant specificationand shown in FIGS. 1 and 2 by providing a signal from left and rightturn signal wires to actuate the electric brakes on the towed vehiclethrough braking circuit blue wire 117 wherein blue wire 117 is at least12 gauge wire having sufficient current carrying capacity. Referring nowto FIG. 1, a second source of power for charger 100 is shown in dashedlines where connection wire 104 is connected to auxiliary power blackwire 114 at connection 109 and to power in terminal 102 on charger 100.Where charger 100 receives power from these parallel sources, a diode108 is inserted into connecting wire 106 to prevent back feeding ofcurrent into the running light circuit through running light green wire112. Such a connection may be desirable for vehicle owners who havepurchased the towing vehicle with a towing package factory installedthereupon. Such a vehicle would already be outfitted with a seven wirecircuit with auxiliary power wire, auxiliary ground wire and brakesignal wire though the brake signal wire would not be connected to abraking system controller unless installed in the towing vehicle. Thus,the electronic braking control system 10 of this invention is useful onvehicles already equipped with a towing package. Second source forcharger 100 may also be a solar array mounted on the trailer (notshown). Additionally, grade and motion device 30 may be powered directlyfrom the auxiliary power wire 114 by extending connecting wire 104 tocircuit breaker 60 as shown with dashed line from connection 109 toterminal 102 and on to terminal 61 of circuit breaker 60. Whereauxiliary power 114 becomes energy source 5, charger 100, battery 20,meter switch 130 and power meter 120 may be omitted from braking controlsystem 10 without comprising the function thereof as long as the towedvehicle remains attached to the towing vehicle, however, thesecomponents may also be retained in braking control system 10 byinserting another diode 108 in connecting wire 64 from battery 20through charger 100 and retaining the connection to power in terminal102 with connecting wire 104 in a “Y” like fashion. In either case,operation of braking control system 10 would remain as described above.

As is readily observed in FIG. 1, charger 100 receives power at power interminal 102 through connecting wire 106 connected at power connection101 to running light circuit green wire 112 of seven wire circuit 110,is grounded at ground terminal 105 to system ground 11 and suppliescharging power to battery 20 through connecting wire 107 connected tocharging terminal 103 on charger 100 and positive battery terminal 21 onbattery 20. As battery 20 is also connected to system ground 11 atnegative terminal 22 a charging circuit is completed from running lightcircuit green wire 112. Battery 20, when used as energy source 5, mayalso be charged externally of electronic braking system 10 utilizingexternal positive terminal 23 and external negative terminal 24.Furthermore, external positive terminal 23 and external negativeterminal 24 may be used to power electronic braking system 10 fromanother energy source 5 onboard the towed vehicle by connecting directlyto the respective terminals of the energy source 5 onboard the towedvehicle, for instance, when battery 20 is dead or has been removed fromelectronic braking system 10. For instance, a boat battery may bedirectly connected to external positive and negative terminals 23, 24respectively with jumper cables or alligator clips to provide for energysource 5. Other energy sources 5 onboard the towed vehicle such asportable AC or DC generators, rectifiers, auxiliary batteries or solarpanels may advantageously be used by connecting through terminals 23,24.

In electronic braking device 10, circuit breaker 60 is provided toprotect grade and motion detection device 30 by interrupting currentflow from energy source 5 in case of large electrical surges. Circuitbreaker 60 is connected to energy source 5 through connecting wire 64,circuit breaker 60 receiving power directly from energy source 5 atfirst terminal 61 with device 30 connected to second terminal 62 throughconnecting wire 63 at power terminal 31. Circuit breaker 60 ispreferably of the interruptible type such that instantaneous surgessometimes found in vehicles does not render electronic braking device 10totally inoperable. Thus, when a momentary surge occurs, circuit breaker60 trips but resets after a specified time, usually about five seconds.In the preferred embodiment in FIG. 2, circuit breaker 60 is generallyincluded in the circuit board of controller 15 but may be added whereina specific controller used as controller 15 does not contain a circuitbreaker therewithin.

In the embodiments shown in figures, electric trailer braking system fora towed vehicle or trailer having at least one pair of wheels fittedwith electrically actuated brakes comprises a self contained electronicbraking control device 10 mounted upon the trailer, braking controldevice 10 comprising means 14 for sensing deceleration of the trailerand means 48 for actuating the electrically actuated brakes of thetrailer upon receiving a signal from the braking system of the towingvehicle. Means 14 for sensing deceleration is an integral part of gradeand motion device 30 and may comprise any of the above mentioned brakecontrollers and may additionally comprise a modified conventional brakecontroller having pendulum or hall effect sensors mounted in anorthogonal array wherein one pendulum or hall effect sensor is adaptedto sense motion in the ±X direction while another pendulum or halleffect sensor senses motion in the ±Y direction. As each is now adaptedto sense motion in a positive or negative direction the function thereofbecomes equivalent to the piezoelectric sensor used in the G-forceindicator. As such, the pendulum or hall effect sensor is also adaptedto sense a change in grade in the ±Z direction. Means 48 for actuatingthe brakes of the towed vehicle comprises the output circuitry ofcontroller 15 blue brake wire 117, safety breakaway switch 70 and energysource 5, these components connected to the brake system of the towedvehicle.

As shown in FIG. 1, grade and motion detection device 30 is connected tobrake control system 10 wherein power is fed to power terminal 31 froman energy source 5, a signal is given to apply a braking signal throughsignal power terminal 32, a brake output is directed to the brakesthrough brake output terminal 33 and ground terminal 34 completes power,signal and braking circuits by grounding to system ground 11 throughground wire 115. A braking signal comprises an electrical impulsethrough the braking light circuit from the towing vehicle by sendingpower through both the right hand turn signal brown wire 111 and lefthand turn signal red wire 113 however, when a turn signal is providedfor either right or left hand turning, power flows only through one ofthese circuits. In this invention, braking signal power comes from thebraking light circuit of the towing vehicle through relay 80 to detectwhen brakes are applied in series with timer 40 to differentiate betweena braking signal and a momentary power signal such as is generated witha four-way emergency flasher system on most modern towing vehicles 54.Wire 83 connects blade 88 of relay 80 to right hand turn brown wire 111at connection 81 which powers one side of a switch internal in relay 80and thus supplies one half of the braking signal to device 30, however,as the internal switch must be activated by a signal through anelectromagnetic coil also internal in relay 80, power must also flowthrough wire 84 from left hand turn red wire 113 connected to connection82 to blade 86 on relay 80 when a signal is also sent through left handturn red wire 113. Both right hand turn brown wire 111 and left handturn red wire 113 must carry current in order to provide a brakingsignal Therefore, when a current is sent only through right hand turnsignal brown wire 111, power is supplied to blade 88, however sincecurrent is only present in right hand signal brown wire 111, theinternal coil in relay 80 is not activated, the internal switch remainsin the open position and only a right hand signal is generated. As theinternal coil in relay 80 has one end connected to ground terminal blade85, when a left hand turn signal is sent through left hand turn red wire113 a circuit is completed through the internal coil and the internalswitch is moved to a closed position against blade 87 but as no currentflows through right hand turn signal brown wire 111, a braking signal isnot sent from blade 88 to blade 87 and therefore a left turn is onlyindicated. As can be appreciated by those skilled in the art, power toonly one of blades 86, 88 flows when left hand turn signals or righthand turn signals are directed from the towing vehicle and hence nobraking signal is generated as the internal switch between blade 88 andblade 87 remains in the open position or the coil remains inactive. Itshould also be appreciated by those skilled in the art that a brakingsignal would be generated when power flows through both left and righthand turn signal wires 113 and 111 respectively when either the brakesor the emergency flashers on the towing vehicle are activated. Whencurrent flows through both right hand and left hand turn signal wires111, 113 respectively, the internal coil activates closing the internalswitch and current flows from blade 88 to blade 87 on relay 80 throughwire 89 to terminal 42 providing a braking signal to timer 40. Since abraking signal can be generated through use of the emergency flashers,timer 40 differentiates between the momentary pulsing of the emergencyflashers and a steady braking signal by only allowing current of theelectrical impulse to flow through timer 40 having a duration greaterthan a first period. It has been found by the teachings of thisinvention that an emergency flasher signal is less than about 0.75second and hence would not activate detection device 30 as timer 40would not allow current to flow until the first period of at least 0.75second is exceeded and therefore a duration greater than this firstperiod indicates that the towing vehicle brakes have been applied. Oncetimer 40 receives a steady signal of greater than the first period,timer 40 allows current to flow through signal power wire 36 connectedto one terminal 41 of timer 40 to signal power terminal 32 on detectiondevice 30 thereby initiating a braking signal within grade and motiondevice 30. Then, when the grade and motion device 30 senses a change ingrade or motion, a braking signal is passed to the towed vehicle brakesthrough brake output terminal 33 connected to brake circuit blue wire117 of seven wire circuit 110.

Although timer 40 is shown connected between relay 80 and detectiondevice 30, timer 40 could be connected between left hand turn connection82 and blade 86 or between right turn connection 81 and blade 88 orbetween blade 85 and system ground 11 and accomplish the purpose ofproviding a preset time interval to differentiate between a turningsignal and a braking signal. Although a simple capacitor timer may beutilized, any suitable automatically resetting timing device having adelay of from about 0.5 to about 1.5 seconds will suffice. A delay ofshorter duration may cause surging of the electric brakes on the towedvehicle as signal pulses generated by the emergency flashers areapproximately 0.5 second in length and a delay of longer than 1.5seconds may result in unsafe operation of a towing/the towed vehiclecombination.

As shown in FIG. 1, braking control system 10 of this invention also hasa power monitor meter 120 connected to a switch 130 for checking thecondition of battery 20. Switch 130 is connected to positive terminal 21of battery 20 with a connecting wire 133 attached to positive connection131 on switch 130 and to system ground 11 through meter 120.Specifically, switch 130 has connecting wire 134 connected to meterconnection 132 thereon and to switch connection 121 on power meter 120.Connection wire 123 then connects ground connection terminal 122 ofpower meter 120 to negative terminal 22 and system ground 11.

In the preferred embodiment of FIGS. 2 and 3, controller 15 is connectedto brake control system 10 wherein power is fed to power terminal 31from an energy source 5, a signal is given to apply a braking signalthrough signal power terminals 86 and 88, a brake output is directed tothe brakes through brake output terminal 33 and ground terminal 34completes power, signal and braking circuits by grounding to systemground 11 through ground wire 115. As with system 10 in FIG. 1, abraking signal comprises an electrical impulse through the braking lightcircuit from the towing vehicle by sending power through both the righthand turn signal brown wire 111 and left hand turn signal red wire 113however, when a turn signal is provided for either right or left handturning, power flows only through one of these circuits. In thispreferred embodiment, relay 80 and timer 40 are resident within themicroprocessor in controller 15 and differentiate between a brakingsignal and a momentary power signal such as is generated with a four-wayemergency flasher system on most modern towing vehicles 54. Here wire211 is spliced directly onto and thereby connects right hand turn brownwire 111 at right turn connection 81 to controller 15 through terminal88 thus suppling one half of the braking signal. An internal connectingswitch in the microprocessor in controller 15 must be activated by asignal also through wire 213 from left hand turn red wire 113 connectedto left hand turn connection 86 on controller 15. As recited above, anelectrical impulse must flow through each of the right hand turn lightcircuit 111 and the left hand turn light circuit 113 of the towingvehicle in order to provide a braking signal and thus, timer 40 withinmicroprocessor in controller 15 differentiates between the momentarypulsing of the emergency flashers and a steady braking signal by onlyallowing current to flow through timer 40 when the electrical impulsehaving a duration greater than a first period of approximately 0.75second is exceeded. Then, when the grade and motion device 30 withincontroller 15 senses a change in grade or motion, a braking signal ispassed to the towed vehicle brakes through brake output terminal 33connected by braking wire 215 to brake circuit blue wire 117.

Braking control system 10 of this invention provides a presettingcondition to the electric brakes of the towed vehicle by passing aninitial electrical signal equal to approximately 20% of energy source 5directly through grade and motion device 30 from terminal 31 throughbrake output terminal 33 to the electric brakes through theaforementioned circuits when the brake pedal is first depressed to lightthe brake light circuit which draws the electromagnet of the brakeactuating lever against the flat surface inside of the brake drum.Little braking action occurs at this presetting condition as the brakeactuating lever has not begun to move the brake shoes into contact withthe surface of the drum but merely moves the electromagnet into contactsuch that actuation of the brakes may occur more rapidly when grade andmotion device 30 senses a change in motion or grade. For instance, whenthe brake pedal on the towing vehicle is depressed only slightly tolight the brake lights but not slow the vehicles appreciably, theelectromagnet remains in its preset position against the inside flatsurface of the drum and then when the brake pedal on the towing vehicleis depressed further to slow the vehicle, grade and motion device 30senses a change in motion and applies a greater voltage to brake outputterminal 33. In another instance, when the brakes of the towing vehicleare fully applied at the outset of a braking action, grade and motiondevice 30 already senses a change in motion and therefore, after thepreset delay of timer 40, braking power proportional to the sensedchange in motion is immediately applied to the brakes on the towedvehicle. In yet another instance, when the towed vehicle is descending agrade, grade and motion device 30 already has sensed a change in gradeand when the brakes from the towing vehicle are applied, braking poweris applied to the towed vehicle electric brakes in much the same mannerthereby applying a proportional braking voltage at brake output terminal33. Of course, the amount of electric braking signal output by detectiondevice 30 at brake output terminal 33 would depend upon the steepness ofthe grade and/or rate of change in motion.

An accurate 12 volt signal is preferred for the proper operation ofelectronic brake control system 10 of this invention. The accurate 12volt signal may exist at the towing location, especially in oldervehicles, or be provided by a converter box mounted in the rear of thetowing vehicle or may come directly from the towing package on thosevehicles so equipped. Since the accurate 12 volt signal may beestablished at the towing location on the towing vehicle, nointerruption of the automatic onboard computers on modern towingvehicles occurs. Similarly, since the accurate 12 volt signal is notaffected by inoperative light bulbs on the towing vehicle, operation ofelectronic brake control system 10 remains unaffected.

Electronic brake control device 10 of this invention may also be used tocontrol the hydraulic braking system on towed vehicles so equipped.Referring now to FIG. 7, compartment 201 effectively remains as is andcontains an energy source 5 such as battery 20. Compartment 202 retainsgrade and motion device 30 therein wherein one of the brake controllers15 described above is used to sense a change in motion in any direction,output a signal in response to a change in motion and energize andactuate the hydraulic brakes of the towed vehicle. Braking controlsystem 10 still receives charging power through the running lightcircuit wire 113, braking signals through right and left hand turnsignal wires 114 and 116 and is grounded through ground wire 115, thefunctions of the grade and motion device and the electrical connectionsdescribed above remaining essentially the same. In the hydraulic brakingcontrol device of FIG. 7, the braking signal output from terminal 33 ispassed to a pump motor of an integrated hydraulic component 300 whereinhydraulic component 300 provides hydraulic fluid to the hydraulic brakesof the towed vehicle through hydraulic brake line 317. Hydrauliccomponent 300 provides an initial surge of fluid when an initial brakingis sensed from the towing vehicle through braking light circuits 114,116 to initially set the shoes of the hydraulic brakes in closeproximity to the drum surface and thereafter provides a proportionaloutput to the hydraulic brakes upon receiving an increased brakingsignal through output terminal 33 when grade and motion device 30 sensesa change in motion. Braking control device 10 of FIG. 7 is also capableof correcting a swaying motion independent of a signal from the towingvehicle by sensing at least two successive lateral movements of thetowed vehicle in the ±Y direction within a given time, generating aswaying signal upon sensing the lateral movements within controller 15,determining a rate of lateral movement of the towed vehicle, generatinga braking signal within braking control device 10 wherein the brakingsignal is proportional to the rate of lateral movement, energizing thehydraulic brakes of the towed vehicle to initial engagement fromhydraulic component 300 upon generating the swaying signal and applyinghydraulic pressure from hydraulic component 300 to the hydraulic brakesof the towed vehicle proportional to the braking signal. Of course,other electric/hydraulic braking systems may use braking control device10 by connecting terminal 33 of controller 15 to another electricallyactuated component.

For enclosure 1, it is preferred that a powder coated steel or stainlesssteel metal box be constructed to arrange all the components in aneasily accessible manner. For instance, battery compartment 201separates the battery 20 from the electronic circuitry. Batterycompartment 201 may be arranged alongside the electronic circuitry asshown in FIG. 1 but preferably is disposed below the electroniccircuitry. A small battery 20, preferably of the dry cell, sealed typehaving sufficient ampere-hour rating to energize and sustain theelectric brakes of the towed vehicle is installed into batterycompartment 201 of upright enclosure 1 and secured therein. Conventionalmethods of securing a battery into a battery case may advantageously beused. One of the various grade and detection devices 30 as describedherein is securely mounted along with charger 100 within compartment 202of enclosure 1.

In FIG. 1, a five-pole relay 80 is also securely mounted to one of theinterior walls of enclosure 1. Female connector 90 from a standard sevenwire trailer connector set is affixed to one wall of enclosure 1 andmale connector 50 from the set is affixed to another wall of theenclosure, each connector 50, 90 accessible from outside enclosure 1such that connections to the standard male/female set on the towedvehicle and the towing vehicle may be connected to the electronic brakecontrol system 10 without entering enclosure 1 The separable cover 204may have a solar panel (not shown) affixed to the exterior top surfacethereof with connecting wires passing through the cover to the interiorof the enclosure 1. The connecting wires to the solar panel may beprovided with a quick disconnect to enable the separable cover to bereadily separated from the enclosure. A power meter 120 is preferablymounted through a wall of enclosure 1 with a switch 130 for periodicallymanually checking the condition of battery 20. In the FIG. 1 embodiment,enclosure 1 also has charger 100, circuit breaker 60 and timer 40mounted internally thereof. Passing through a wall of enclosure 1 isbreakaway safety switch 70, breakaway safety switch 70 adapted toreceive a component 75 therein which when received, causes breakawaysafety switch 70 to be a normally open switch. In FIG. 2, compartment201 contains energy source 5 as described above and compartment 202 hascharger 100 and controller 15 securely mounted therein. Connecting wires211, 212, 213 and 117 pass from compartment 202 downwardly into andthrough compartment 201 with wires 105, 107 passing into compartment 201from compartment 202, these wires connected to energy source 5. Groundwire 215 is shown connected to negative terminal 22 of batter 20,however it is fully understood that other means of providing a systemground may be employed without departing from the scope of thisinvention. Compartment 201 is typically provided with L-shaped brackets203 having mounting holes 199 provided therethrough for mounting system10 to tongue 200 of a trailer by passing a mounting screw 196 througheach of holes 199 into holes 198 in crosspiece 197 of tongue 200. Wires211, 212, 213 and 215 are then connected to the wiring loom 51 of thetrailer with conventional T-shaped or bullet splice connectors readilyavailable on the market. Wire 117 is connected to the lead in connectionof each of the electric brake elements on the wheels of the trailer.Preferably, cover 204 slips over the outside walls of compartment 202and is sealingly affixed thereto with screws through the side flanges ofcover 204. Likewise, the periphery of the lower flange of compartment202 is slightly larger than periphery of compartment 201 such thatcompartment 202 may be sealingly affixed to compartment 201 with screwsthrough the lower side flanges thereof Where another onboard energysource is used for energy source 5, brackets 203 may be provided oncompartment 202 wherein compartment 202 is secured to tongue 200.Enclosure 1 may be provided in a color to effectively match the color ofthe towed vehicle.

This invention provides for a method of controlling the braking of atowed vehicle using a self contained electronic braking control device10 onboard the towed vehicle, braking control device 10 comprising anenergy source 5, means 14 for sensing deceleration of the towed vehicle,means for generating a braking signal and means for energizing andactuating the brakes of the towed vehicle. The method comprises thesteps of sensing deceleration of the towed vehicle, determining a rateof deceleration of the towed vehicle, sensing a braking signal from atowing vehicle towing the towed vehicle, generating a braking signalwithin braking control device 10 wherein the braking signal isproportional to the rate of deceleration, energizing and actuating thebrakes of the towed vehicle to initial engagement from energy source 5upon sensing the braking signal from the towing vehicle and applyingenergy from energy source 5 to the brakes of the towed vehicleproportional to the braking signal. In like manner, a method ofcontrolling the swaying of a towed vehicle using a self containedelectronic braking control device 10 onboard the towed vehicle isprovided. Self contained braking control device 10 comprises an energysource 5, means 14 for sensing deceleration of the towed vehicle, meansfor generating a swaying signal, means for generating a braking signaland means 48 for energizing and actuating the brakes of the towedvehicle. The method comprises the steps of sensing at least twosuccessive lateral movements of the towed vehicle in the ±Y directionwithin a given time, generating a swaying signal upon sensing thelateral movements, determining a rate of lateral movement of the towedvehicle, generating a braking signal within braking control device 10wherein the braking signal is proportional to the rate of lateralmovement, energizing the brakes of the towed vehicle to initialengagement from energy source 5 upon generating the swaying signal andapplying energy from energy source 5 to the brakes of the towed vehicleproportional to the braking signal.

While the present invention has been described with reference to theabove described preferred embodiments and alternate embodiments, itshould be noted that various other embodiments and modifications may bemade without departing from the spirit of the invention. Therefore, theembodiments described herein and the drawings appended hereto are merelyillustrative of the features of the invention and should not beconstrued to be the only variants thereof nor limited thereto.

I claim:
 1. In a hydraulic braking system of a trailer having at leastone pair of wheels fitted with hydraulically actuated brakes, theimprovement wherein said trailer braking system contains a selfcontained electronic braking control device mounted upon said trailer,said braking control device comprising a means for sensing decelerationof said trailer including a G-force indicator which senses a change inmotion in any direction simultaneously along all orthogonal axes andoutput a signal proportional to the algebraic sum of said change inmotion along said orthogonal axes, and means for actuating a motor ofsaid hydraulically actuated brakes of said trailer independent of asignal from a vehicle towing said trailer.
 2. A hydraulic trailerbraking system as in claim 1 wherein said signal is an electricalsignal, said electrical signal linear from a null point to a maximum. 3.A hydraulic trailer braking system as in claim 2 wherein said controllersends electric power to said motor on said trailer proportional to saidelectrical signal from said G-force indicator.
 4. A hydraulic trailerbraking system as in claim 1 wherein said signal is a digital signal,said digital signal linear from a null point to a maximum.
 5. Ahydraulic trailer braking system as in claim 4 wherein said brakecontroller converts said digital signal to an analog signal and sendselectric power to said motor on said trailer proportional to saiddigital signal from said G-force indicator.
 6. In a braking systemcomprising a towed vehicle having at least one pair of wheels fittedwith hydraulically actuated brakes and a towing vehicle havingelectrical braking lighting circuitry, the improvement wherein saidbraking system comprises a self contained electronic braking controldevice mounted upon said towed vehicle, said braking control devicecomprising a means for sensing deceleration of said towed vehicle whichsimultaneously senses a change in velocity in ±X direction, ±Y directionand a change in grade perpendicular to a plane defined by said ±X, and±Y directions, means for connecting said electric braking circuitry ofsaid towing vehicle to a pump motor of an integrated hydraulic componentconnected to said hydraulically actuated brakes of said towed vehicleand means for actuating said hydraulically actuated brakes of said towedvehicle, said means for actuating comprising a braking signalestablished in said electrical braking lighting circuitry of said towingvehicle.
 7. A braking system as in claim 6 wherein said braking signalcomprises an electrical impulse through the right hand turn lightcircuit and the left hand turn light circuit of said braking lightingcircuit of said towing vehicle.
 8. A braking system as in claim 7wherein said hydraulically actuated brakes of said towed vehicle areautomatically energized to an initial engagement state upon sensing saidbraking signal from said towing vehicle.
 9. A braking system as in claim7 wherein said electrical impulse has a duration greater than a firstpre-determined period, said first period comprising a time interval todifferentiate between a momentary turning signal and a steady brakingsignal in said left hand turn light circuit and said right hand turnlight circuit.
 10. A braking system as in claim 9 wherein said firstperiod is between 0.5 second and 1.5 seconds.
 11. An electric trailerbraking system as in claim 10 wherein said first period is greater than0.75 second.
 12. A braking system as in claim 6 wherein said means forsensing outputs an electrical signal to said integrated hydrauliccomponent proportional to said change in velocity.
 13. A braking systemas in claim 12 wherein said integrated hydraulic component appliesbraking force to at least one of said at least one pair of wheels.
 14. Abraking system as in claim 9 wherein said initial engagement statecomprises an initial surge of fluid to said hydraulically actuatedbrakes of said at least one said pair of said wheels from saidintegrated hydraulic component thereby setting the shoes of saidhydraulic brakes in close proximity to the drum surface of said at leastone said pair of said wheels.